Widening the Operative Corridor-Evaluating the Transcortical Approach to Giant Falcine Meningiomas

BACKGROUND

Giant falcine meningiomas are surgically complex as they are deep in location, concealed by normal brain parenchyma, in close proximity to various neurovascular structures, and frequently involve the falx bilaterally. Although classically accessed using a bifrontal craniotomy and interhemispheric approach, little data exist on alternative operative corridors for these challenging tumors. We evaluated perioperative and long-term outcomes in patients undergoing transcortical resection of giant bilateral falcine meningiomas.

METHODS

From 2013 to 2022, fourteen patients with giant bilateral falcine meningiomas treated via a transcortical approach at our institution were identified. Perioperative and long-term outcomes were evaluated to determine predictors of adverse events. Corticectomy depth was also analyzed to determine if it correlated with increased postoperative seizure rates.

RESULTS

57.1% of cases were WHO grade 2 meningiomas. Average tumor volume was 77.8 ± 46.5 cm3 and near/gross total resection was achieved in 78.6% of patients. No patient developed a venous infarct or had seizures in the 6 months after surgery. Average corticectomy depth was 0.83 ± 0.71 cm and increasing corticectomy depth did not correlate with higher risk of postoperative seizures (P = 0.44). Increasing extent of tumor resection correlated with lower tumor grade (P = 0.011) and only 1 patient required repeat resection during a median follow-period of 24.9 months.

CONCLUSIONS

The transcortical approach is a safe alternative corridor for accessing giant, falcine meningiomas, and postoperative seizures were not found to correlate with increasing corticectomy depth. Further prospective studies are necessary to determine the best approach to these surgically complex lesions.

Transradial or Transulnar Long Sheath Access to the Brachial Artery Allows for Neuroendovascular Procedures in Patients with Radial or Ulnar Artery Occlusion

BACKGROUND

Transradial access is an important tool for many neuroendovascular procedures. Occlusion of the radial or ulnar artery is not uncommon after transradial or transulnar access and can present a challenge for patients requiring repeat angiography.

METHODS

Between March 2022 and June 2023, patients undergoing transradial or transulnar angiography who were found to have a radial artery occlusion or ulnar artery occlusion were identified. Repeat catheterization of the occluded artery was attempted using a 21-gauge single wall puncture needle and a 0.021-inch wire to traverse the occlusion and insert a 23-cm sheath into the brachial artery.

RESULTS

A total of 25 patients undergoing 26 angiograms during the study period were found to have a radial artery occlusion or ulnar artery occlusion. Successful repeat catheterization of the occluded artery was achieved in 21 of 26 cases (80.7%). Outer diameter sheath size ranged from 5 Fr (0.0655 inch) to 8 Fr (0.1048 inch). No access complications were encountered. Number of prior angiograms, time since prior angiogram, and prior angiogram procedure time were associated with lower likelihood of successful access.

CONCLUSIONS

Transradial or transulnar neuroangiography through an occluded radial or ulnar artery is safe and feasible by traversing the occlusion into the brachial artery with a 23-cm sheath. Repeat catheterization is most successful in patients with an arterial occlusion <6 months old. This technique is important in patients who have limited options for arterial access, avoiding access site complications inherent in transfemoral access, and in patients who specifically require radial or ulnar artery access.

National reduction in cerebral arteriovenous malformation treatment correlated with increased rupture incidence

BACKGROUND

Recently, there has been a shift in management of unruptured cerebral arteriovenous malformations (AVMs) following studies suggesting that medical management alone was superior to interventional therapy.

OBJECTIVE

To evaluate the influence of contemporary AVM management on AVM rupture patterns in the United States.

METHODS

154 297 AVM admissions were identified between 2003 and 2017 in the National Inpatient Sample. Annual AVM intervention and rupture rates were computed and multivariable logistic regression assessed the likelihood of AVM intervention pre- and post-2014. Segmented regression identified significant change points and fitted segmented linear models for annual intervention and rupture rates. Correlation coefficients assessed the relationship between annual AVM intervention and rupture rates.

RESULTS

For unruptured AVMs, intervention likelihood and proportion decreased after 2014 (28.1% to 22.3%, p<0.0001; adjusted OR=0.857, 95% CI 0.751 to 0.977, p=0.02). Ruptured AVM admissions increased from 14.7% to 18.6% after 2014 (p<0.0001). Between 2003 and 2017, segmented linear regression identified one significant change point in intervention rate between 2014 and 2015. Average annual percent change for rupture incidence and intervention rate increased by 0.49% (p=0.0001) and decreased by 1.17% (p=0.0001), respectively. Annual AVM intervention rates were inversely correlated with annual AVM rupture incidence (Pearson coefficient=-0.82, p=0.0002). In 2017, the annual AVM rupture rate (20.6%) surpassed the annual AVM intervention rate (19.7%).

CONCLUSIONS

After 2014, the likelihood of intervention for unruptured AVMs decreased while the incidence of ruptured AVMs increased. These findings suggest that fewer unruptured AVM treatments may lead to increases in AVM rupture incidence.

Transradial Access Failures During Neuroangiography for Patients With Moyamoya

BACKGROUND

Despite studies continuing to demonstrate the utility of transradial access (TRA) in neuroangiography, minimal data exist regarding predictors of TRA failure. Furthermore, although many patients with moyamoya disease/syndrome will require life-long angiographic evaluation, even less has been reported on the usage of TRA in this population.

OBJECTIVE

To perform a matched analysis at our high-volume moyamoya center to determine predictors of TRA failure in these patients.

METHODS

A total of 636 patients undergoing TRA for neuroangiography were identified from 2018 to 2020. Demographic and angiographic characteristics including radial artery spasm (RAS), radial anomalies, and access site conversion were compared between patients with moyamoya and the rest of the cohort. A 4:1 matched analysis, based on age and sex, was also performed to eliminate confounding variables.

RESULTS

Patients with moyamoya were younger (40 vs 57 years, P < .0001), had smaller radial diameters (1.9 vs 2.6 mm, P < .0001), more commonly had a high brachial bifurcation (25.9% vs 8.5%, P = .008), more frequently experienced clinically significant RAS (40% vs 8.4%, P < .0001), and more often required access site conversion (26.7% vs 7.8%, P = .002). Increasing age was associated with less TRA failures in patients with moyamoya (odds ratio = 0.918) but more failures in the rest of the cohort (odds ratio = 1.034). In the matched analysis, patients with moyamoya continued to experience more radial anomalies, RAS, and access site conversions.

CONCLUSION

Patients with moyamoya, when controlling for age and sex, have higher rates of TRA failure during neuroangiography. Increasing age in Moyamoya is inversely correlated with TRA failures suggesting that younger patients with moyamoya are at higher risk of extracranial arteriopathy.

Predictors and outcomes of first pass efficacy in posterior circulation strokes: Insights from STAR collaboration

Background: First-pass efficacy (FPE) has been established as an important predictor of favorable functional outcomes after endovascular thrombectomy (ET) in anterior circulation strokes. In this retrospective cohort study, we investigate predictors and clinical outcomes of FPE in posterior circulation strokes (pcAIS). Methods: The Stroke Thrombectomy and Aneurysm Registry database was used to identify pcAIS patients who achieved FPE. Their baseline characteristics and outcomes were compared with the non-FPE group. The primary outcome was a 90-day modified Rankin Scale (mRS) of 0-3. Univariate (UVA) and multivariate (MVA) analyses were done to evaluate predictors of FPE. Safety outcomes included distal emboli, vessel rupture, symptomatic intracranial hemorrhage, and mortality. Results: Of 359 patients, 179 (50%) achieved FPE. Clot burden, occlusion site, and ET technique-related variables were similar between the two groups except for shorter procedure time with FPE. The primary outcome was significantly better with FPE (56.4% vs. 32.8%, p < 0.001). Complications were similar except for a higher rate of distal emboli in non-FPE group (11.1% vs. 3.2%, p = 0.032). Atrial fibrillation (Afib) had increased odds (aOR: 2.06, 95% CI; 1.24, 3.4, p = 0.005) and prior ischemic stroke had decreased odds (aOR: 0.524, 95% CI; 0.28, 0.97, p = 0.04) of FPE. Afib was the only independent predictor of FPE on MVA (1.94, 95% CI; 1.1, 3.43, p = 0.022). Conclusions: Higher rate of FPE in Afib-related pcAIS could possibly be explained by the differences in clot composition and degree of in-situ atherosclerotic disease burden. Future studies are warranted to explore the relationship of clot composition with ET outcomes.

Telescoping pipeline vantage embolization devices with shield technology for the treatment of a giant, symptomatic dolichoectatic basilar trunk aneurysm

Background:

Dolichoectatic basilar trunk aneurysms are exceedingly rare and carry a poor prognosis. Treatment strategies are often reserved for patients with severe and progressive symptoms.

Case Description:

A patient in their 40s with a dolichoectatic basilar trunk aneurysm developed significant progression of the lesion and neurologic decline, necessitating treatment. He underwent flow diversion utilizing multiple telescoping Pipeline Vantage Embolization Devices with Shield Technology for treatment. At 1-year follow-up, the aneurysm was stable in size and the patient remained at his neurologic baseline.

Conclusion:

This case illustrates the need for continued development of next-generation endovascular devices as these aneurysms have limited management options.

Radial Long Sheath Angioplasty for Proximal Severe Flow Limiting Radial Artery Spasm Utilizing the Dotter Technique

BACKGROUND

Although studies continue to demonstrate the advantages of transradial access (TRA) for neurointerventions, radial artery spasm (RAS) remains a frequent cause of TRA failure. Dotter initially described a technique to dilate areas of peripheral vascular stenosis by advancing sequentially larger catheters across the lesion over a wire. We present our institutional experience performing a modified Dotter technique utilizing long radial sheaths to dilate areas of proximal flow limiting RAS.

OBJECTIVE

To review the use of the Dotter technique for alleviating RAS in patients undergoing TRA for neurointerventions.

METHODS

A retrospective review of all patients undergoing TRA for neurointerventions at our institution from 2018-2020 was performed to identify patients with proximal flow limiting RAS. In identified patients, a modified Dotter technique was employed to dilate the stenosis. Demographic and periprocedural data were assessed to identify any adverse outcomes.

RESULTS

Four patients with severe proximal flow limiting RAS were identified. In each case, a hydrophilic long radial sheath and vascular dilator were sequentially advanced through the stenosis. In all cases, repeat angiography demonstrated improvement of the spasm and final radial angiograms demonstrated persistent improvement in caliber and regularity of the vessel. Each procedure was also completed via TRA with no periprocedural complications.

CONCLUSIONS

Our modified Dotter technique is effective in bypassing areas of severe proximal flow limiting RAS thus obviating the need for access site conversion. Additional studies are warranted to understand the implication of the angioplasty-like effects seen within the radial artery following removal of the long radial sheaths.

Supralesional Ablation Volumes Are Feasible in the Posterior Fossa and May Provide Enhanced Symptomatic Relief

BACKGROUND

Laser interstitial thermal therapy (LITT) for posterior fossa lesions remains rare as the small size of the infratentorial compartment, proximity to the brainstem, and thickness/angulation of the occipital bone creates barriers to procedural success. Furthermore, evaluation of the effect of ablation volume on outcomes is limited.

OBJECTIVE

To analyze our institutional experience with LITT in the posterior fossa stratifying perioperative and long-term outcomes by ablation volumes.

METHODS

Seventeen patients with posterior fossa lesions treated with LITT from 2013 to 2020 were identified. Local progression-free survival (PFS), overall survival, steroid dependence, and edema reduction were evaluated with Kaplan-Meier analysis grouped by ablation volume. Preoperative, postoperative, and last known Karnofsky Performance Status (KPS) were compared using a matched paired t test.

RESULTS

No differences in pathology, preoperative KPS, or preoperative lesion volume were found between patients with total (100%-200% increase in pre-LITT lesion volume) versus radical (>200% increase in pre-LITT lesion volume) ablations. Patients who underwent radical ablation had a higher postoperative KPS (93 vs 82, P = .02) and higher KPS (94 vs 87, P = .04) and greater reduction in perilesional edema at last follow-up (P = .01). Median follow-up was 80.8 wk.

CONCLUSION

Despite obvious anatomical challenges, our results demonstrate that radical ablations are both feasible and safe in the posterior fossa. Furthermore, radical ablations may lead to greater decreases in perilesional edema and improved functional status both immediately after surgery and at last follow-up. Thus, LITT should be considered for patients with otherwise unresectable or radioresistant posterior fossa lesions.

Republished: Manual reduction of a radial artery loop under direct fluoroscopic visualization

Transradial access has become increasingly used in neurointerventions because it reduces access site complications. However, radial artery anomalies can be difficult to navigate, often necessitating conversion to femoral access. We describe the case of a female patient in her early 70 s who underwent preoperative embolization of a carotid body tumor via right transradial access. Her radial angiogram demonstrated the presence of a radial artery loop which was successfully navigated with a triaxial system but would not spontaneously reduce even after the guide catheter was advanced into the subclavian artery. However, manual manipulation of the catheters in the antecubital fossa under direct fluoroscopic visualization reduced the loop allowing the procedure to continue transradially. Although a majority of radial loops can be traversed and reduced using standard techniques, this case demonstrates that manual reduction can be successful when other measures fail. We recommend attempting this method before converting the access site.

Manual reduction of a radial artery loop under direct fluoroscopic visualization

Transradial access (TRA) has become increasingly utilized in neurointerventions because it reduces access site complications. However, radial artery anomalies can be difficult to navigate, often necessitating conversion to femoral access. We describe the case of a female patient in her early 70s who underwent preoperative embolization of a carotid body tumor via right TRA. Her radial angiogram demonstrated the presence of a radial artery loop which was successfully navigated with a triaxial system but would not spontaneously reduce, even after the guide catheter was advanced into the subclavian artery. However, manual manipulation of the catheters in the antecubital fossa under direct fluoroscopic visualization reduced the loop, allowing the procedure to continue transradially. Although most radial loops can be traversed and reduced using standard techniques, this case demonstrates that manual reduction can be successful when other measures fail. We recommend attempting this method prior to converting the access site.

Transient ipsilateral mydriasis following carotid artery stenting

BACKGROUND AND IMPORTANCE

One of the most feared and devastating complications of carotid revascularization procedures is hyperperfusion hemorrhage. The acute onset of an ipsilateral mydriatic pupil following carotid endarterectomy (CEA) or carotid artery stenting (CAS) should prompt immediate neurosurgical evaluation to rule out hyperperfusion injury.

CLINICAL PRESENTATION

We describe a case of benign, transient ipsilateral mydriasis following CAS. After undergoing right common and internal carotid artery (ICA) angioplasty and stenting with distal embolic protection, the patient developed anisocoria with a right-sided 5 mm minimally reactive pupil. Imaging demonstrated no acute pathology, and the mydriasis resolved spontaneously within 48 hours. We hypothesise that the pathophysiologic mechanism is secondary to transient ischemia of parasympathetic structures within the petrous/cavernous ICA from arterial ostium occlusion that occurred during device placement. Alternatively, sympathetic stimulation during angioplasty is also plausible.

CONCLUSIONS

Although an ipsilateral mydriatic pupil following carotid revascularization necessitates evaluation, it may represent a self-limiting process especially in the absence of other focal neurologic deficits.

Upper extremity transvenous access for neuroendovascular procedures: an international multicenter case series

BACKGROUND

Radial artery access for transarterial procedures has gained recent traction in neurointerventional due to decreased patient morbidity, technical feasibility, and improved patient satisfaction. Upper extremity transvenous access (UETV) has recently emerged as an alternative strategy for the neurointerventionalist, but data are limited. Our objective was to quantify the use of UETV access in neurointerventions and to measure failure and complication rates.

METHODS

An international multicenter retrospective review of medical records for patients undergoing UETV neurointerventions or diagnostic procedures was performed. We also present our institutional protocol for obtaining UETV and review the existing literature.

RESULTS

One hundred and thirteen patients underwent a total of 147 attempted UETV procedures at 13 centers. The most common site of entry was the right basilic vein. There were 21 repeat puncture events into the same vein following the primary diagnostic procedure for secondary interventional procedures without difficulty. There were two minor complications (1.4%) and five failures (ie, conversion to femoral vein access) (3.4%).

CONCLUSIONS

UETV is safe and technically feasible for diagnostic and neurointerventional procedures. Further studies are needed to determine the benefit over alternative venous access sites and the effect on patient satisfaction.

Navigating radial artery loops in neurointerventions

BACKGROUND

Although studies continue to demonstrate lower complications in neurointerventions using transradial access (TRA) compared with transfemoral approaches, anatomic radial variants can be difficult to navigate and remain one of the frequent causes of access site conversion.

OBJECTIVE

To evaluate predictors of TRA failure in neuroendovascular patients with radial loops and suggest a protocol for managing these anomalies.

METHODS

A prospective collection of patients undergoing TRA at participating institutions from July 2018 to September 2020 was reviewed. Patients with a radial loop were identified. Patient demographics and procedural characteristics were evaluated to determine predictors of both TRA failure and successful reduction of the radial loop.

RESULTS

We identified 32 transradial neurointerventions in which patients had radial loops. Twenty-two (68.8%) were identified by diagnostic angiography, and the majority were performed for evaluation or treatment of an aneurysm (56.3%). TRA failure occurred in 13 (40.6%) of the cohort and happened more frequently in patients over 60 years of age (p=0.01) and those with recurrent radial artery diameters ≤2 mm (p=0.02). Of the 19 patients who had successful TRA, 12 (63.2%) procedures were performed through the recurrent radial artery.

CONCLUSION

Although radial loops are associated with high transradial failure rates, our results suggest that the presence of a loop is not an absolute contraindication to TRA. Therefore, we recommend attempting loop navigation using our protocol. Patient age, vascular tortuosity, and recurrent radial artery size should help dictate when to convert to an alternative access site.

Neuro-oncology practice guidelines from a high-volume surgeon at the COVID-19 epicenter

BACKGROUND

During the coronavirus 19 (COVID-19) pandemic, physicians have begun adapting their daily practices to prevent transmissions. In this study we aimed to provide surgical neuro-oncologists with practice guidelines during the COVID-19 pandemic based on objective data from a high-volume brain tumor surgeon at the current COVID-19 epicenter.

METHODS

All outpatient visits and surgeries performed by the senior author during the COVID-19 pandemic were compared between the initial quarantine (3/23/20-5/4/20), the plateau period following quarantine (5/5/20-6/27/20), and the second peak (6/28/20-7/20/20). In-person and telemedicine visits were evaluated for crossovers. Surgeries were subdivided based on lesion type and evaluated across the same time period.

RESULTS

From 3/23/20-7/20/20, 469 clinic visits and 196 surgeries were identified. After quarantine was lifted, face-to-face visits increased (P < 0.01) yet no change in telehealth visits occurred. Of 327 telehealth visits, only 5.8% converted to in-person during the 4-month period with the most cited reason being patient preference (68.4%). Of the 196 surgeries performed during the pandemic, 29.1% occurred during quarantine, 49.0% during the plateau, and 21.9% occurred in the second peak. No COVID negative patients developed symptoms at follow-up. 55.6% were performed on malignant tumors and 31.6% were benign with no difference in case volumes throughout the pandemic.

CONCLUSIONS

Despite exceptional challenges, we have maintained a high-volume surgical neuro-oncology practice at the epicenter of the COVID-19 pandemic. We provide the protocols implemented at our institution in order to maximize neuro-oncology care while mitigating risk of COVID-19 exposure to both patients and providers.

Implementation of a radial long sheath protocol for radial artery spasm reduces access site conversions in neurointerventions

BACKGROUND

Many neurointerventionalists have transitioned to transradial access (TRA) as the preferred approach for neurointerventions as studies continue to demonstrate fewer access site complications than transfemoral access. However, radial artery spasm (RAS) remains one of the most commonly cited reasons for access site conversions. We discuss the benefits, techniques, and indications for using the long radial sheath in RAS and present our experience after implementing a protocol for routine use.

METHODS

A retrospective review of all patients undergoing neurointerventions via TRA at our institution from July 2018 to April 2020 was performed. In November 2019, we implemented a long radial sheath protocol to address RAS. Patient demographics, RAS rates, radial artery diameter, and access site conversions were compared before and after the introduction of the protocol.

RESULTS

747 diagnostic cerebral angiograms and neurointerventional procedures in which TRA was attempted as the primary access site were identified; 247 were performed after the introduction of the long radial sheath protocol. No significant differences in age, gender, procedure type, sheath sizes, and radial artery diameter were seen between the two cohorts. Radial anomalies and small radial diameters were more frequently seen in patients with RAS. Patients with clinically significant RAS more often required access site conversion (p<0.0001), and in our multivariable model use of the long sheath was the only covariate protective against radial failure (OR 0.061, 95% CI 0.007 to 0.517; p=0.0103).

CONCLUSION

In our experience, we have found that the use of long radial sheaths significantly reduces the need for access site conversions in patients with RAS during cerebral angiography and neurointerventions.

Malignant Peripheral Nerve Sheath Tumor of the C2 Nerve Root: Case Report

Here we present the case of a 36-year-old man who was found to have a symptomatic malignant neural sheath tumor growing from the C2 nerve root following a period of progressively worsening headaches. The patient was successfully treated with surgical resection resulting in resolution of cranial nerve deficits. Though uncommon, malignant peripheral nerve sheath tumor must be considered in the differential diagnosis of tumors involving the cervical nerve roots and carotid space.

ISGylation governs the oncogenic function of Ki-Ras in breast cancer

Aberrant expression of the oncogenic Kirsten-Ras (Ki-Ras) and interferon-stimulated gene 15 (ISG15) pathways is common in breast and other cancers. However, whether these dysregulated pathways cooperate to promote malignancy is not known. This study links Ki-Ras and ISG15 in a previously unidentified regulatory loop that may underlie malignant transformation of mammary cells. We show that oncogenic Ki-Ras regulates the expression of the ISG15 pathway (free ISG15 and ISG15 conjugates), and ISG15, in turn, stabilizes Ki-Ras protein by inhibiting its targeted degradation via lysosomes in breast cancer cells. Disruption of this loop by silencing either Ki-Ras or the ISG15 pathway restored the disrupted cellular architecture, a hallmark feature of most cancer cells. We also demonstrate that ISG15 and UbcH8 (ISG15-specific conjugating enzyme) shRNAs reversed Ki-Ras mutation-associated phenotypes of cancer cells, such as increased cell proliferation, colony formation, anchorage-independent growth in soft agar, cell migration, and epithelial-mesenchymal transition. As UbcH8-silenced breast cancer cells are devoid of ISG15 conjugates but have free ISG15, our results using UbcH8-silenced cells suggest that ISG15 conjugates, and not free ISG15, contributes to oncogenic Ki-Ras transformation. We have thus identified the conjugated form of ISG15 as a critical downstream mediator of oncogenic Ki-Ras, providing a potential mechanistic link between ISG15 and Ki-Ras-mediated breast tumorigenesis. Our findings, which show that inhibition of the ISGylation reverses the malignant phenotypes of breast cancer cells expressing oncogenic Ki-Ras, support the development of ISG15 conjugation inhibitors for treating breast and also other cancers expressing oncogenic Ki-Ras.

Modulation of alpha-catenin Tyr phosphorylation by SHP2 positively effects cell transformation induced by the constitutively active FGFR3

The Src homology 2 phosphotyrosyl phosphatase (SHP2) is a nonreceptor-type phosphatase that acts as a positive transducer of receptor Tyr kinase (RTK) signaling, particularly the Ras-REK and PI3K-Akt pathways. Recently, we have demonstrated that SHP2 is required for cell transformation induced by the constitutively active fibroblast growth factor receptor 3 (K/E-FR3) (Oncogene, 22, 6909-6918). In that study, we had detected a phosphotyrosyl protein of approximately 100 KDa (p100) in cells expressing dominant-negative SHP2 (R/E-SHP2), but its identity and relevance in SHP2-meditaed transformation was not known. Here, we report the identification of p100 as alpha-catenin, a vinculin-related protein involved in adherens junction-mediated intercellular adhesion. We show that alpha-catenin becomes Tyr phosphorylated in intercellular adhesion-dependent manner and this event is counteracted by SHP2. Substrate trapping in intact cells and immunocomplex phosphatse assays confirmed that alpha-catenin is in deed an SHP2 substrate. Tyr phosphorylation of alpha-catenin enhances its translocation to the plasma membrane and its interaction with beta-catenin, leading to enhanced actin polymerization and stabilization of adherens junction-mediated intercellular adhesion, a phenomenon commensurate with loss of the transformation phenotype. Site-directed mutagenesis studies also suggested that Tyr phosphorylation of alpha-catenin enhances its inhibitory role on cell transformation. Based on our previous work and the current report, we demonstrate that mediation of cell transformation by SHP2 is a complex process that involves modulation of the Ras-ERK and PI3K-Akt signaling pathways, intercellular adhesion, focal adhesion and actin cytoskeletal reorganization. To our knowledge, this is the first report showing regulation of alpha-catenin function by Tyr phosphorylation and its inhibitory effect on cell transformation.

Difficult cases in heart failure: familial dilated cardiomyopathy

While originally thought to be uncommon, familial dilated cardiomyopathy may occur quite often. Aside from symptoms of heart failure, these forms of dilated cardiomyopathy may be associated with arrhythmias and sudden death. The case detailed describes such a patient and emphasizes the importance of a careful family history. Also discussed is the importance of screening of first- and second-degree relatives of these patients. (c)2001 by CHF, Inc.

Current use of endovascular grafts for the treatment of abdominal aortic aneurysms

The development of endovascular techniques for the treatment of abdominal aortic aneurysms has significantly reduced the major morbidity associated with standard surgical repair. The indications for use of endovascular grafts and the limitations of their use have not been fully defined. The effectiveness of the numerous commercially fabricated devices is currently being evaluated. This article describes the general principles of use for endovascular devices and details the features and results for the devices in current use.

Expression and immunogenicity of hemagglutinin A from Porphyromonas gingivalis in an avirulent Salmonella enterica serovar typhimurium vaccine strain

Porphyromonas gingivalis is a major etiologic agent of periodontitis, a chronic inflammatory disease that ultimately results in the loss of the supporting tissues of the teeth. Previous work has demonstrated the usefulness of avirulent Salmonella enterica serovar Typhimurium strains as antigen delivery systems for protective antigens of pathogens that colonize or cross mucosal surfaces. In this study, we constructed and characterized a recombinant S. enterica serovar Typhimurium avirulent vaccine strain which expresses hemagglutinin A and carries no antibiotic resistance markers. HagA, a major virulence-associated surface protein, is a potentially useful immunogen that contains an antigenic epitope which, in humans, elicits an immune response that is protective against subsequent colonization by P. gingivalis. The hagA gene, including its promoter, was cloned into a balanced-lethal Salmonella vector and transferred to the vaccine strain. Heterologous expression of HagA was demonstrated in both Escherichia coli JM109 and S. enterica serovar Typhimurium vaccine strain chi4072. The HagA epitope was present in its native configuration as determined by immunochemistry and immunoelectron microscopy. Purified recombinant HagA was recognized by sera from mice immunized with the S. enterica serovar Typhimurium vaccine strain. The HagA-specific antigen of the vaccine was also found to be recognized by serum from a periodontal patient. This vaccine strain, which expresses the functional hemagglutinin protein, induces a humoral immune response against HagA and may be useful for developing a protective vaccine against periodontal diseases associated with P. gingivalis.

Porphyromonas gingivalis virulence factors and invasion of cells of the cardiovascular system

Our laboratory is interested in the genes and gene products involved in the interactions between Porphyromonas gingivalis (Pg) and the host. These interactions may occur in either the periodontal tissues or other non-oral host tissues such as those of the cardiovascular system. We have previously reported the cloning of several genes encoding hemagglutinins, surface proteins that interact with the host tissues, and are investigating their roles in the disease process. Primary among these is HagA, a very large protein with multiple functional groups that have significant sequence homology to protease genes of this species. Preliminary evidence indicates that an avirulent Salmonella typhimurium strain containing hagA is virulent in mice. These data indicate that HagA may be a key virulence factor of Pg. Additionally, we are investigating the invasion of primary human coronary artery endothelial cells (HCAEC) by Pg because of the recent epidemiological studies indicating a correlation between periodontal disease (PD) and coronary heart disease (CHD). We found that some, but not all, strains of Pg are able to invade these cells. Scanning electron microsopy of the infected HCAEC demonstrated that the invading organisms initially attached to the host cell surface as aggregates and by a "pedestal"-like structure. By transmission electronmicroscopy it could be seen that internalized bacteria were present within multimembranous compartments localized with rough endoplasmic reticulum. In addition, invasion of the HCAEC by Pg resulted in an increase in the degradation of long-lived cellular proteins. These data indicate that Pg are present within autophagosomes and may use components of the autophagic pathway as a means to survive intracellularly. However, Pg presence within autophagosomes in KB cells could not be observed or detected. It is therefore likely that Pg uses different invasive mechanisms for different host cells. This and the role of HagA in invasion is currently being investigated further.

Comparison of treatment plans for lower extremity arterial occlusive disease made with electrocardiography-triggered two-dimensional time-of-flight magnetic resonance angiography and digital subtraction angiography

BACKGROUND

The purpose of the study was to determine whether preoperative treatment plans for patients with lower extremity ischemia can be made with electrocardiography (EKG)-triggered two-dimensional (2D) time-of-flight (TOF) magnetic resonance angiography (MRA) as accurately as digital subtraction angiography (DSA).

METHODS

Forty patients were prospectively evaluated with the combination of EKG-triggered 2D TOF MRA, DSA, and pulse volume recordings. Blinded reviewers graded arterial segments for disease severity. Accuracy of separate MRA- and DSA-based treatment plans was compared with the procedures performed based on all available information.

RESULTS

There was an 86% exact match between MRA- and DSA-based plans (92% MRA and 94% DSA accuracy). The MRA-based plan accurately predicted 90% of suprainguinal and 95% of infrainguinal procedures, whereas the DSA-based plan accurately predicted 100% of suprainguinal and 85% of infrainguinal procedures. Two-year primary patency was 83% for all procedures. Radiologists' review of disease severity resulted in a mean exact correlation between studies of 81% (kappa = 0.64). The agreement between radiologists interpreting the MRA was 84% (kappa = 0.7) compared with 82% (kappa = 0.66) for the DSA.

CONCLUSIONS

MRA- and DSA-based preoperative management plans were of comparable efficacy. Significant interobserver variability was seen with the interpretations of both preoperative studies. EKG-triggered 2D TOF MRA can be used to plan arterial reconstructions; however, all patients require arterial pressure measurements prior to suprainguinal repair and confirmatory intraoperative angiography during infrainguinal revascularization.

Multiple sclerosis care: an integrated disease-management model

A disease-management model must be integrated, comprehensive, individual patient focused and outcome driven. In addition to high quality care, the successful model must reduce variations in care and costs. MS specialists need to be intimately involved in the long-term care of MS patients, while not neglecting primary care issues. A nurse care manager is the "glue" between the managed care company, health care providers and the patient/family. Disease management focuses on education and prevention, and can be cost effective as well as patient specific. To implement a successful program, managed care companies and health care providers must work together.

A randomized trial of intravenous heparin in conjunction with anistreplase (anisoylated plasminogen streptokinase activator complex) in acute myocardial infarction: the Duke University Clinical Cardiology Study (DUCCS) 1

OBJECTIVES

We designed a randomized trial to evaluate the effects of heparin administration in conjunction with anistreplase (anisoylated plasminogen streptokinase activator complex [APSAC]) on arterial patency and clinical end points.

BACKGROUND

The role of conjunctive intravenous heparin therapy with APSAC has not been tested despite the recommendations that intravenous heparin should be used.

METHODS

Four hours after APSAC administration, 250 patients with acute myocardial infarction were randomly assigned to receive 325 mg of either aspirin alone or aspirin and a continuous infusion of heparin (15 IU/kg body weight per h). Clinical ischemic events and bleeding complications were monitored. On hospital day 5, coronary arteriography and left ventriculography were performed.

RESULTS

The primary end point of the trial (the combined outcome of death, reinfarction, recurrent ischemia and occlusion of the infarct-related artery) occurred in 42% of the heparin-treated group versus 43% of the group treated without heparin (p = 0.94). A patent infarct-related artery was present in 80% of the patients treated with heparin and in 73% of those treated without heparin (p = 0.26). Left ventricular function, as measured by ejection fraction, was well preserved in both groups (52% vs. 50.5%, respectively, p = 0.29). The overall bleeding rate was higher in patients with (32%) than without (17.2%) heparin (p = 0.006).

CONCLUSIONS

Weight-adjusted intravenous heparin therapy after APSAC in acute myocardial infarction does not reduce the combined incidence of death, reinfarction, recurrent ischemia and occlusion of the infarct-related artery. Furthermore, withholding intravenous heparin therapy is associated with a 46% reduction in bleeding complications. Our findings do not support the addition of intravenous heparin after APSAC therapy, as currently recommended, and suggest that a strategy of withholding heparin is simpler and safer and does not place the patient at increased risk for ischemic complications after myocardial infarction.

Health care costs of veterans with multiple sclerosis: implications for the rehabilitation of MS. VA Multiple Sclerosis Rehabilitation Study Group

We retrospectively determined health care costs among veterans with multiple sclerosis (MS) and correlated the costs with neurologic dysfunction. Total health care costs for the 165 patients averaged $35,000/year. VA benefits and homecare together accounted for 85% of the total costs. Total health care costs correlated with two measures of neurologic dysfunction, the Expanded Disability Status Scale (EDSS) (r = 0.61, p < 0.001) and the Incapacity Status Scale (ISS) (r = 0.64, p < 0.001). The costs of VA benefits, homecare, and hospitalizations also correlated with the EDSS, ISS, and other measures of neurologic dysfunction whereas the cost of outpatient clinic visits did not. In a period of three years, there were 40 hospitalizations, at a total cost of $412,800, that were potentially preventable with appropriate outpatient management. Improving selfcare and avoiding preventable hospitalizations might lower the considerable health care costs of MS.

Myelin basic protein and proteolipid protein reactivity of brain- and cerebrospinal fluid-derived T cell clones in multiple sclerosis and postinfectious encephalomyelitis

T cells were directly cloned from autopsied MS brain plaque tissue and reactivity was measured with the major encephalitogenic neuroantigens, myelin basic protein (MBP), and proteolipid protein (PLP). Control clones were simultaneously derived from the blood. The proportion of T4+ and T8+ T cell clones from the brain tissue differed from that of peripheral blood T cell clones derived at the same time, suggesting that the clones were not derived from the peripheral blood. None of 57 brain-derived T cell clones proliferated to either MBP or PLP, although they responded well to PHA and IL 2. An additional 235 clones derived from the cerebrospinal fluid and 126 clones from the peripheral blood of other subjects with multiple sclerosis also did not proliferate to MBP or PLP. In contrast, five of nine T4+ clones from the CSF of a subject with postinfectious encephalomyelitis exhibited low but clear reactivity to human MBP, supporting the possible role of MBP as the target antigen in this disease. These studies, the first to clone T cells directly from MS plaque tissue, suggest that the lack of consistent T cell reactivity to MBP or PLP in the peripheral blood of MS patients does not appear to be secondary to the sequestration of a large number of these cells in the brain.

Myelin basic protein and proteolipid protein reactivity of brain- and cerebrospinal fluid-derived T cell clones in multiple sclerosis and postinfectious encephalomyelitis

T cells were directly cloned from autopsied MS brain plaque tissue and reactivity was measured with the major encephalitogenic neuroantigens, myelin basic protein (MBP), and proteolipid protein (PLP). Control clones were simultaneously derived from the blood. The proportion of T4+ and T8+ T cell clones from the brain tissue differed from that of peripheral blood T cell clones derived at the same time, suggesting that the clones were not derived from the peripheral blood. None of 57 brain-derived T cell clones proliferated to either MBP or PLP, although they responded well to PHA and IL 2. An additional 235 clones derived from the cerebrospinal fluid and 126 clones from the peripheral blood of other subjects with multiple sclerosis also did not proliferate to MBP or PLP. In contrast, five of nine T4+ clones from the CSF of a subject with postinfectious encephalomyelitis exhibited low but clear reactivity to human MBP, supporting the possible role of MBP as the target antigen in this disease. These studies, the first to clone T cells directly from MS plaque tissue, suggest that the lack of consistent T cell reactivity to MBP or PLP in the peripheral blood of MS patients does not appear to be secondary to the sequestration of a large number of these cells in the brain.

Breathing pattern during and after exercise of different intensities

We recently observed rapid shallow breathing during recovery from maximal exercise in some normal subjects. We wondered whether this phenomenon is randomly related to level of exercise or is limited to recovery from very high levels of exercise. We monitored ventilation, tidal volume, and respiratory frequency in seven normal subjects during and after exercise. Each subject exercised on several occasions on separate days. At least two of the tests were maximal (i.e., subject terminated). In the other tests exercise was terminated by the experimenter at different fractions of the highest level attained by the subject. There was no systematic difference between breathing pattern during exercise and recovery in tests where final O2 consumption (VO2) was 45-92% of the subjects' highest VO2. By contrast 13 of 19 studies in which final VO2 was 92-100% of highest VO2 were followed by relative rapid shallow breathing. We conclude that rapid shallow breathing during recovery from exercise is a phenomenon that is limited to very high exercise levels. On consideration of the various mechanisms that may be entertained to explain this phenomenon, we believe that development of pulmonary congestion-interstitial edema at very high levels of exercise is the most consistent with our findings.

Prognostic implications of ventricular arrhythmias during 24 hour ambulatory monitoring in patients undergoing cardiac catheterization for coronary artery disease

The prognostic importance of ventricular arrhythmias detected during 24 hour ambulatory monitoring was evaluated in 395 patients with and 260 patients without significant coronary artery disease. Ventricular arrhythmias were found to be strongly related to abnormal left ventricular function. A modification of the Lown grading system (ventricular arrhythmia score) was the most useful scheme for classifying ventricular arrhythmias according to prognostic importance. When only noninvasive characteristics were considered, the score contributed independent prognostic information, and the complexity of ventricular arrhythmias as measured by this score was inversely related to survival. However, when invasive measurements were included, the ventricular arrhythmia score did not contribute independent prognostic information. Furthermore, ejection fraction was more useful than the ventricular arrhythmia score in identifying patients at high risk of sudden death.